1. Field of the Invention
This application claims priority to Japanese Application Number 2007-162846 filed on 20 Jun. 2007 and incorporated herein in its entirety by reference.
The present invention relates to an abrasive cleaning agent, a method for manufacturing the same, and a method for polishing using the above abrasive cleaning agent, and more particularly relates to an abrasive cleaning agent comprised of an elastic material used as a core material and abrasive grains which are compounded therewith or which are supported, carried and/or surrounded on surfaces of the elastic material, a method for manufacturing the abrasive cleaning agent, and a method for polishing using the same for polishing an article to be treated (hereunder, simply called a “workpiece”) to form a mirror surface or the like.
2. Description of the Related Art
According to a known lapping technique in which a workpiece is polished to form a mirror surface or the like, it has been difficult to polish a workpiece having a complicated three-dimensional shape, a microfabricated workpiece, or the microfabricated part of a workpiece, and hence in recent years, a technique has been developed in which a polishing process as described above is performed by ejecting an abrasive cleaning agent onto a workpiece.
The polishing process using an abrasive cleaning agent, as described above, is performed by ejecting an abrasive polishing agent, a so-called “elastic abrasive”, which is an agent including an elastic material, such as a synthetic rubber or a synthetic resin, used as a core material and fine abrasive grains which are supported on surfaces of the elastic material or which are compounded therewith. When the abrasive cleaning agent as described above is used, a cutting force applied to a workpiece is reduced, and the polishing process can be performed on the workpiece to form a mirror surface or the like without forming irregularities and so forth on a surface of the workpiece.
An example of a polishing process using the abrasive cleaning agent as described above is a process in which an abrasive cleaning agent is ejected in a dry state onto a workpiece using a blasting machine.
In addition, a process has been proposed in which diamond abrasive grains, which are processed with an aqueous “multi-solution” instead of the above-described elastic material, such as a synthetic rubber or a synthetic resin, are ejected onto a workpiece.
In addition, although not for the purpose of polishing a workpiece to form a mirror surface or the like, the applicant of the present invention has proposed the use of dried and pulverized underground tubers of devil's tongue starch (devil's tongue: also called “konjak” or “konnyaku” which is a jelly-like food made from the starch of devil's tongue; scientific name: Amorphophallus konjac, hereinafter also called “tubers of devil's tongue”) as an abrasive cleaning agent for a blasting process, such as flash (burr) removal (deburring), removal of adhering material, removal of coated films, and cleaning, to be performed on a workpiece instead of an abrasive cleaning agent obtained by pulverizing known food grains and seed shells (see Japanese Unexamined Patent Application Publication No. 2001-38629, and Japanese Patent No. 3899209).
Among the abrasive cleaning agents used in these described related techniques, when the abrasive cleaning agent in which abrasive grains are supported on an elastic material, such as a synthetic rubber or a synthetic plastic, or are compounded therewith is disposed of after use, it is not naturally decomposed by biodegradation or the like even if buried in the ground, and when the abrasive cleaning agent is processed by incineration or the like, for example, CO2 and other harmful gases are generated; hence, when the abrasive cleaning agent is disposed of, the environmental burden is increased. Accordingly, the above abrasive cleaning agent does not meet the current social demand which requires products and the like to have a low environmental burden.
In addition, in the case in which a polishing process is performed using the abrasive cleaning agent as described above, when the above abrasive cleaning agent containing a synthetic rubber or a synthetic resin as the elastic material is used under dry conditions, static electricity is generated, and hence, for example, dust in the air, the abrasive grains, a crushed powder generated in the process, or the like may disadvantageously adhere to the workpiece due to this static electricity. Furthermore, for example, the abrasive cleaning agent may adhere to an inside wall of a cabinet in the blasting machine, and hence problems may arise in that circulation and/or recovery of the abrasive cleaning agent cannot be easily performed.
Furthermore, when a synthetic resin material, such as a melamine resin material, is used as the elastic material, in addition to the above-described problems, as a result of ejecting to and collision with the workpiece, the abrasive cleaning agent and, in particular, the elastic material may be crushed. As a result, since the crushing ratio is high, and the amount of abrasive cleaning agent which can be reused after being recovered is small, the cost therefor is increased. In addition, the working environment may be diminished in some cases due to the generation of a large amount of dust.
It has been conceived that, in order to decrease the crushing ratio, a synthetic rubber or a synthetic plastic used as the elastic material should be foamed to further increase the elasticity so that crushing is unlikely to occur. However, since the bulk density of an abrasive cleaning agent using the foamed elastic material as described above is decreased, the processability thereof is diminished, and as a result, the conditions for process are restricted such as ejection has to be performed on a workpiece at high pressure or at high velocity.
On the other hand, according to a known technique in which diamond abrasive grains which are processed with a predetermined aqueous solution are ejected, the problem of electrostatic generation is solved since the abrasive grains are ejected with the aqueous solution; however, the aqueous solution, which is used together with the diamond abrasive grains, adheres to the workpiece, and as a result, the workpiece is contaminated thereby. In particular, when the workpiece is formed of a material which is liable to rust, such as steel, in order to prevent the generation of rust caused by the adhering aqueous solution, as described above, the aqueous solution adhering to the workpiece must be removed as soon as possible, and the operation for doing so is very complicated.
In addition, as described above, the applicant of the present invention has proposed the abrasive cleaning agent formed by using devil's tongue as a raw material (disclosed in Japanese Unexamined Patent Application Publication No. 2001-38629); however, although this abrasive cleaning agent can be used for deburring, removal of adhering material, removal of coated films, cleaning, and the like without changing the surface of a workpiece into a satin finished surface, this abrasive cleaning agent cannot be used for a polishing process in which a surface of a workpiece is actively processed to form a mirror surface or the like.
Accordingly, the present invention has been conceived in order to solve the problems of the above related techniques, and an object of the present invention is to provide an abrasive cleaning agent that can solve the above problems, a method for manufacturing the same, and a method for polishing using the abrasive cleaning agent. By using this abrasive cleaning agent, a surface of a workpiece can be easily polishing processed into a mirror surface or the like by using a relatively simple method in which the abrasive cleaning agent is ejected onto the workpiece, and furthermore, in addition to suppressed generation of static electricity and reduced contamination adhering to the workpiece, recycling of the abrasive cleaning agent can be performed since the crushing ratio thereof is small. In addition, since the specific gravity of the abrasive polishing agent is high, even when it is ejected at a relatively low ejection pressure and/or ejection velocity, the workpiece can be suitably processed. Furthermore, in the case in which the abrasive cleaning agent is disposed of after use, it can be returned to the ground by biodegradation or the like when being buried therein, and also, even in the case in which an incineration treatment is performed on the abrasive cleaning agent, it is not necessary to be concerned with the generation of CO2 gas and other harmful gases.